x01.Weiqi.8: 一点改进

原来的代码全部删除，进行了深层次重构，得其意而忘其言。得意之处有二：

1.关于显示

以 StoneSize 属性为依托，在 set 中加了一句：Width = Height = m_StoneSize * 19；以此来控制棋盘大小。所有的对象在 Init（） 方法中创建，而具体的渲染在 Redraw（） 方法中完成。这种创建与重绘相分开的办法，使调整大小时进行重绘更简单易行。这两个方法的代码如下：

void Init()
        {
            // 线
            for (int i = 0; i < 19; i++) {
                m_LinesH[i] = new Line();
                m_LinesH[i].Stroke = Brushes.Black;
                m_Canvas.Children.Add(m_LinesH[i]);

                m_LinesV[i] = new Line();
                m_LinesV[i].Stroke = Brushes.Black;
                m_Canvas.Children.Add(m_LinesV[i]);
            }

            // 星
            for (int j = 0; j < 3; j++) {
                for (int i = 0; i < 3; i++) {
                    m_Stars[i, j] = new Ellipse();
                    m_Stars[i, j].Fill = Brushes.Black;
                    m_Canvas.Children.Add(m_Stars[i, j]);
                }
            }

            for (int i = 0; i < 19; i++) {
                for (int j = 0; j < 19; j++) {
                    m_Stones[i, j] = new Ellipse();
                    m_Stones[i, j].Visibility = Visibility.Hidden;
                    m_Canvas.Children.Add(m_Stones[i, j]);

                    m_Numbers[i, j] = new TextBlock();
                    m_Numbers[i, j].Background = Brushes.Transparent;
                    m_Numbers[i, j].Visibility = Visibility.Hidden;
                    m_Canvas.Children.Add(m_Numbers[i, j]);

                    m_Steps[i, j] = new Step();
                    m_Steps[i, j].Row = i;
                    m_Steps[i, j].Col = j;
                    m_EmptySteps.Add(m_Steps[i, j]);
                    m_AllSteps.Add(m_Steps[i, j]);
                }
            }

            // 当前标志
            m_CurrentRect.Visibility = System.Windows.Visibility.Hidden;
            m_CurrentRect.Fill = Brushes.Red;
            m_Canvas.Children.Add(m_CurrentRect);

            for (int i = 0; i < 19; i++) {
                for (int j = 0; j < 19; j++) {
                    Rectangle rect = new Rectangle();
                    rect.Visibility = System.Windows.Visibility.Hidden;
                    m_EmptyRects[i, j] = rect;
                    m_Canvas.Children.Add(m_EmptyRects[i,j]);

                }
            }
        }

public void Redraw()
        {
            // 画线
            for (int i = 0; i < 19; i++) {
                Line l = m_LinesH[i];
                int y = i * StoneSize + StoneSize / 2;
                l.X1 = StoneSize / 2;
                l.Y1 = y;
                l.X2 = 19 * StoneSize - StoneSize / 2;
                l.Y2 = y;

                l = m_LinesV[i];
                int x = i * StoneSize + StoneSize / 2;
                l.X1 = x;
                l.Y1 = StoneSize / 2;
                l.X2 = x;
                l.Y2 = 19 * StoneSize - StoneSize / 2;
            }

            // 画星
            for (int j = 0; j < 3; j++) {
                for (int i = 0; i < 3; i++) {
                    Ellipse e = m_Stars[i, j];
                    e.Width = e.Height = StoneSize / 3;
                    double left = 4 * StoneSize + j * 6 * StoneSize - StoneSize / 2 - e.Width / 2;
                    double top = 4 * StoneSize + i * 6 * StoneSize - StoneSize / 2 - e.Height / 2;
                    Canvas.SetLeft(e, left);
                    Canvas.SetTop(e, top);
                }
            }

            // Stones and Numbers
            for (int i = 0; i < 19; i++) {
                for (int j = 0; j < 19; j++) {
                    var stone = m_Stones[i, j];
                    stone.Width = stone.Height = StoneSize;
                    Canvas.SetLeft(stone, j * StoneSize);
                    Canvas.SetTop(stone, i * StoneSize);

                    ShowNumber(i, j, m_Steps[i, j].StepCount);
                }
            }

            // 点目标志
            if (IsShowMesh)
                for (int i = 0; i < 19; i++) {
                    for (int j = 0; j < 19; j++) {
                        var rect = m_EmptyRects[i, j];
                        rect.Width = rect.Height = m_CurrentRect.Width;
                        double offset = (StoneSize - rect.Width) / 2.0;
                        Canvas.SetLeft(rect, j * StoneSize + offset);
                        Canvas.SetTop(rect, i * StoneSize + offset);
                    }
                }
        }

        public bool NextOne(int row, int col)
        {
            if (m_Steps[row, col].StoneColor != StoneColor.Empty)
                return false;
            if (m_BanOnce.Row == row && m_BanOnce.Col == col) {
                return false;
            }
            m_BanOnce.Row = m_BanOnce.Col = -1;

            DrawStep(row, col);
            bool isBlack;
            if (m_Steps[row, col].StoneColor == StoneColor.Black) {
                m_BlackSteps.Add(m_Steps[row, col]);
                isBlack = true;
            } else {
                m_WhiteSteps.Add(m_Steps[row, col]);
                isBlack = false;
            }
            m_EmptySteps.Remove(m_Steps[row, col]);

            UpdateBlackBlocks();
            UpdateWhiteBlocks();
            if (isBlack) {
                if (!UpdateDeadBlocks(m_WhiteBlocks))
                    UpdateDeadBlocks(m_BlackBlocks);
            } else {
                if (!UpdateDeadBlocks(m_BlackBlocks))
                    UpdateDeadBlocks(m_WhiteBlocks);
            }

            MoveCurrentRect();

            m_StepCount++;

            StoneColor selfColor = isBlack ? StoneColor.Black : StoneColor.White;
            bool isKillSelf = m_DeadBlocks.ContainsKey(m_StepCount - 1)
                    && m_DeadBlocks[m_StepCount - 1].Steps.Count == 1
                    && m_DeadBlocks[m_StepCount - 1].Steps[0].StoneColor == selfColor;
            if (isKillSelf) {
                m_DeadBlocks.Remove(m_StepCount - 1);
                BackOne();
                return false;
            }

            return true;
        }

2.关于提子

以 LinkSteps（）方法为依托，提子不再是上下左右一通乱吃了，而是采用集合的办法，只需看看一块棋有没有气即可。其代码如下：

//   +
        // + + +    与 step 相连的棋子，包含自身
        //   +        根据 color 参数决定是所有，同色，黑色，白色，还是空色。
        List<Step> LinkSteps(Step step, StoneColor color = StoneColor.Empty)
        {
            List<Step> links = new List<Step>();
            for (int i = -1; i < 2; i++) {
                for (int j = -1; j < 2; j++) {
                    if (i == j || i == -j) {
                        continue;
                    }
                    if (InRange(step.Row + i, step.Col + j)) {
                        links.Add(m_Steps[step.Row + i, step.Col + j]);
                    }
                }
            }
            links.Add(step);
            if (color == StoneColor.All) {
                return links;
            } else {
                links.RemoveAll(l => l.StoneColor != color);
                return links;
            }
        }

当然，关于劫争，关于悔棋，非深入代码，不能明白。但 LinkSteps（）是构成集合的基础。从集合的观点，研究围棋，相信比其他方法更为可行。